It is well known that the economic life expectancy of commercially productive oil and gas wells is determined by a transitional change with time from the well being predominantly oil and gas producing to becoming increasingly a producer of water. Another reason for the diminution of oil and gas production is the loading up of a wellbore due to formation water influx.
It is commonly known that increasing water production from the formation into the wellbore results in a situation where the weight of water in the wellbore is such that the pressure exerted by the water is greater than the producing reservoir pressure and consequentially production of oil and gas ceases.
This process is of particular interest in free flowing oil and gas wells and applies specifically to many oil and gas wells located in offshore areas.
There are well established methods to unload water from such a well either by nitrogen or inert gas injection or by coiled tubing gas lift methods; however, such methods, if applied without first stopping the incoming water problem, have little chance of sustaining the resultant oil and/or gas production for any length of time before the water influx again loads up the well and the well again becomes uneconomic.
The gel and polymer emplacement methodologies disclosed in U.S. Pat. Nos. 6,431,280 and 6,615,918, which are incorporated herein by reference, are ideally suited to stopping unwanted water flow into such normally free flowing wells prior to unloading the water.